The name Asmodai is believed to derive from Avestan language*aēšma-daēva, where aēšma means "wrath", and daēva signifies "demon" or "divine being". While the daēvaAēšma is thus Zoroastrianism's demon of wrath and is also well attested as such, the compound aēšma-daēva is not attested in scripture. It is nonetheless likely that such a form did exist, and that the Book of Tobit's "Asmodaios" (Ἀσμοδαῖος) and the Talmud's "Ashmedai" (אשמדאי) reflect it.[6] In the Zoroastrian and Middle Persiandemonology, did exist the conjuncted form khashm-dev, where the word dev was the same of daeva.[7]

The spellings Asmodai,[8][9]Asmodee,[10][11]Osmodeus,[12][13] and Osmodai[14][15] have also been used. The name is alternatively spelled in the bastardized forms (based on the basic consonants אשמדאי, ʾŠMDʾY) Hashmedai (חַשְמְדּאָי, Hašmədʾāy; also Hashmodai, Hasmodai, Chashmodai, Chasmodai),[16][17][18][19]Hammadai (חַמַּדּאָי, Hammadʾāy; also Chammadai),[20][21]Shamdon (שַׁמְדּוֹן, Šamdōn),[22] and Sidonai (שִׁדֹנאָי, Šidonʾāy).[21] Some traditions have subsequently identified Shamdon as the father of Asmodeus.[22]

The Jewish Encyclopedia of 1906 rejects the otherwise accepted etymological relation between the Persian "Æshma-dæva" and Judaism's "Ashmodai" claiming that the particle "-dæva" could not have become "-dai" and that Æshma-dæva as such—a compound name—never appears in Persian sacred texts. Still, the encyclopedia proposes that the "Asmodeus" from the Apocrypha and the Testament of Solomon are not only related somewhat to Aeshma but have similar behaviour, appearance and roles,[23] to conclude in another article under the entry "Aeshma", in the paragraph "Influence of Persian Beliefs on Judaism"[24] that Persian Zoroastrian beliefs could have heavily influenced Judaism's theology on the long term, bearing in mind that in some texts there are crucial conceptual differences while in others there seems to be a great deal of similarity, proposing a pattern of influence over folk beliefs that would extend further to the mythology itself in general.

The full name "Ashmedai" is not found, but in 2 Kings 17:30, a certain Ashima appears as the false god for whom the Syrian Hamathites made an idol. Not only does this name better resemble that of the Persian daeva Aeshma, but the name (אֲשִׁימָא) also greatly resembles the name Ashmedai (אַשְמְדּאָי) in Hebrew. Likewise, the Bible is clear in that at least some heathen gods are not just idols, but representations of demons in Deut 32:17 and Psa 106:37.

The Asmodeus of the Book of Tobit is hostile to Sarah, Raguel's daughter, (Tobit 6:13); and slays seven successive husbands on their wedding nights, impeding the sexual consummation of the marriages. He is described as 'the worst of demons'. When the young Tobias is about to marry her, Asmodeus proposes the same fate for him, but Tobias is enabled, through the counsels of his attendant angel Raphael, to render him innocuous. By placing a fish's heart and liver on red-hot cinders, Tobias produces a smoky vapor that causes the demon to flee to Egypt, where Raphael binds him (Tobit 8:2-3). According to some translations Asmodeus is strangled.

Perhaps Asmodeus punishes the suitors for their carnal desire, since Tobias prays to be free from such desire and is kept safe. Asmodeus is also described as an evil spirit in general: 'Ασμοδαίος τὸ πονηρὸν δαιμόνιον or τõ δαιμόνιον πονηρόν, and πνεῦμα ἀκάθαρτον (Tobit 3:8; Tobit 3:17; Tobit 6:13; Tobit 8:3).

The figure of Ashmedai in the Talmud is less malign in character than the Asmodeus of Tobit. In the former, he appears repeatedly in the light of a good-natured and humorous fellow. But besides that, there is one feature in which he parallels Asmodeus, inasmuch as his desires turn upon Solomon's wives and Bath-sheba.

Another legend depicts Asmodai throwing king Solomon over 400 leagues away from the capital by putting one wing on the ground and the other stretched skyward. He then changed places for some years with King Solomon. When King Solomon returned, Asmodai fled from his wrath.[26] Similar legends can be found in islamic folklore. There Asmodeus is called Sakhr (Arabic: صخر‎ the Rock or the Stony One), because in islamic lore, Solomon banished him into a rock, after he takes his kingdom back from him. There he counts as the king of the jinn.[27]

Another passage describes him as marrying Lilith, who became his queen.[28]

He has also been recorded as the off-spring of the union between Adam and the angel of prostitution, Naamah, conceived while Adam was married to Lilith.[citation needed]

In the Testament of Solomon, a 1st–3rd century text, the king invokes Asmodeus to aid in the construction of the Temple. The demon appears and predicts Solomon's kingdom will one day be divided (Testament of Solomon, verse 21–25).[29] When Solomon interrogates Asmodeus further, the king learns that Asmodeus is thwarted by the angel Raphael, as well as by sheatfish found in the rivers of Assyria. He also admits to hating water and birds because both remind him of God.

In the Malleus Maleficarum (1486), Asmodeus was considered the demon of lust.[30]Sebastien Michaelis said that his adversary is St. John. Some demonologists of the 16th century assigned a month to a demon and considered November to be the month in which Asmodai's power was strongest. Other demonologists asserted that his zodiacal sign was Aquarius but only between the dates of January 30 and February 8.

He has 72 legions of demons under his command. He is one of the Kings of Hell under Lucifer the emperor. He incites gambling, and is the overseer of all the gambling houses in the court of Hell. Some Catholic theologians compared him with Abaddon. Yet other authors considered Asmodeus a prince of revenge.

Asmodai appears as the king 'Asmoday' in the Ars Goetia, where he is said to have a seal in gold and is listed as number thirty-two according to respective rank.[32]

He "is strong, powerful and appears with three heads; the first is like a bull, the second like a man, and the third like a ram; the tail of a serpent, and from his mouth issue flames of fire."[33] Also, he sits upon an infernal dragon, holds a lance with a banner and, amongst the Legions of Amaymon, Asmoday governs seventy two legions of inferior spirits.[32]

The story of Asmodeus and Solomon has a reappearance in Arabian and Islamic lore, however Asmodeus is commonly named Sakhr (rock) probably a reference to his fate, because according to Islamic lore, after Solomon defeated Asmodeus, he imprisioned him inside a box of rock, chained with iron, and throw it into the sea.[37]Tabari linked Asmodeus to Surah 37:106 of the Quran in his work Annals of al-Tabari, therefore Solomon was replaced by Asmodeus over forty days.[38]

Asmodeus' reputation as the personification of lust continued into later writings, as he was known as the "Prince of Lechery" in the 16th century romance Friar Rush.[39] The French Benedictine Augustin Calmet equated his name with fine dress.[39] The 16th century Dutch demonologist Johann Weyer described him as the banker at the baccarat table in hell, and overseer of earthly gambling houses.[40]

In 1641, the Spanish playwright and novelist Luis Velez de Guevara published the satirical novel El diablo cojuelo, where Asmodeus is represented as a mischievous demon endowed with a playful and satirical genius. The plot presents a rascal student that hides in an astrologer's mansard. He frees a devil from a bottle. As an acknowledgement the devil shows him the apartments of Madrid and the tricks, miseries and mischiefs of their inhabitants.[41][42] The French novelist Alain-René Lesage adapted the Spanish source in his 1707 novel le Diable boiteux,[39] where he likened him to Cupid. In the book, he is rescued from an enchanted glass bottle by a Spanish student Don Cleophas Leandro Zambullo. Grateful, he joins with the young man on a series of adventures before being recaptured. Asmodeus is portrayed in a sympathetic light as good-natured, and a canny satirist and critic of human society.[39] In another episode Asmodeus takes Don Cleophas for a night flight, and removes the roofs from the houses of a village to show him the secrets of what passes in private lives. Following Lesage's work, he was depicted in a number of novels and periodicals, mainly in France but also London and New York.[43]

Asmodeus was widely depicted as having a handsome visage, good manners and an engaging nature; however, he was portrayed as walking with a limp and one leg was either clawed or that of a rooster. He walks aided by two walking sticks in Lesage's work, and this gave rise to the English title The Devil on Two Sticks[31] (also later translated The Limping Devil and The Lame Devil). Lesage attributes his lameness to falling from the sky after fighting with another devil.[44]

On 18 February 1865, author Evert A. Duyckinck sent President Abraham Lincoln a letter, apparently mailed from Quincy. Duyckinck signed the letter “Asmodeus”, with his initials below his pseudonym. His letter enclosed a newspaper clipping about an inappropriate joke allegedly told by Lincoln at the Hampton Roads Peace Conference. The purpose of Duyckinck’s letter was to advise Lincoln of “an important omission” about the history of the conference. He advised that the newspaper clipping be added to the “Archives of the Nation”.[45]

Asmodeus is referred to and briefly described in the short story "The Mirror", by Isaac Bashevis Singer.

^Stave, Erik (2002) [1901–1906]. "Æshma (Asmodeus, Ashmedai)". In Singer, Isidore; Adler, Cyrus et al. Jewish Encyclopedia. New York: Funk & Wagnalls. LCCN16-014703. Retrieved 7 March 2018. since it is paralleled by the later Pahlavi-form "Khashm-dev" ("Khashm dev" = "Æshma dev"), written with the Aramaic "sheda," but pronounced "dev." [..] Asmodeus (Ashmedai) embodies an expression of the influence that the Persian religion or Persian popular beliefs have exercised on the Jewish—an influence that shows itself very prominently in the domain of demonology. CS1 maint: Uses editors parameter (link)